1. Field of Invention
This invention relates to an apparatus for forming a workpiece having a separable forming element in which the workpiece is formed and in which, when the elements are separated, the workpiece must be removed from one of the elements, and is particularly directed to improved means for ejecting the workpiece or dislodging it.
2. Prior Art
In molding apparatus and the like, the workpiece has to be ejected or removed from the mold and for this purpose ejecting rods are arranged to be pushed up through the mold in contact with the workpiece and to dislodge it from the mold. It has been found in practice, however, that such ejectors tend merely to loosen the workpiece and that manual intervention is necessary to complete removal of the workpiece from the mold.
It has been proposed (U.S. Pat. No. 3,893,644) to modify such apparatus by inserting therein means for accelerating or multiplying the speed and length of travel of such ejectors. In one such device referred to in the art as an accelerated ejector, the device comprises two racks operating on a pinion, so that when one rack is depressed, the other one is raised. Thus, when the device is mounted on the ejector plate of a mold with one of the racks affixed to an ejector pin and the other arranged to abut a stud projecting downwardly from the mold when the ejector plate is moved upwardly to move ejector pins upwardly, the one attached to the rack will be moved up at twice the rate of the other. This results from the fact that as the ejector plate is moving the ejector pin up one unit, the accelerator or multiplier is moving the other one up two units. Such devices are difficult to install since they require machining in its ejector plate of an irregular hole and are, moreover, limited to the aforesaid two to one ratio. Thus, for every unit length one rack is pushed down, the other one goes up one unit length, so that as the ejector plate moves up one unit length, each ejector pin is moved up one unit length and, simultaneously, as the rack is depressed by the stud, the other and, consequently, the ejector pin attached thereto, moves up a second unit length. Hence, the maximum and only overall ratio obtainable in such device is a two to one ratio and the maximum ratio in the device itself is one to one, that is, one unit length of the rack down gives one unit length of the other rack up, and vice versa.